Example scenario: A male patient who has had one previous heart attack consults with his GP. The patient asks if there are any drugs that can reduce the chance of him dying from another heart attack. The GP talks about administering simvastatin, but is unsure how effective this might be. He promises to find some evidence to show the patient before his next consultation.

Using PICO to formulate a question:

In patients who have had a heart attack, does simvastatin reduce mortality?

This is a Treatment (therapy) question, so after performing our search, we need to restrict our results to randomised controlled trials in the first instance. You might want to open PubMed to follow our example searches: www.pubmed.com